WA is awesome! But it's also MASSIVE so it's hard to say what you'll expect.
Bunbury and Albany are both in the south, so the climate is very different from the rest of the state. The land is more lush and forested, and the coast is more rugged. It's very very pretty down there. January will be summertime so it will be hot, but not as hot as other places. The south is also great if you're a wine lover!
Broome is way up in the North so the climate is very different. If you'll be there in January, you'll be there in the middle of the wet season so make sure you bring good raingear! It will still be hot, but very rainy. If you'll be there for the full year, in the winter months will be the dry season so you should see LOTS of sunshine. Broome is the most beautiful place I have ever been - the sunset on cable beach I don't think you could ever get sick of. The town itself is a mix between aboriginals and people involved in tourism so it's an interesting culture...
You may be in the middle somewhere. One the coast there are 'big towns' such as Geraldton and Carnarvon but there are also some big mining towns far from the coast, such as Kalgoorlie. These places are hot and dry, like a desert. Especially in January, which is the summer.
The big thing for you will probably be culture shock. Rural WA is mostly populated with aboriginals, farmers, and people involved in mining. Depending on what town you're in you could get a different mix of these types of people.
As for transit - I never had to rely on this, I always travelled with tours (or by plane to Broome). I remember staying in hostels and seeing notice boards for people driving to various places, so you might want to go to a hostel to look for rides. It also might be worth investing in a car, just so you aren't completely isolated. There are probably buses between the bigger towns and Perth, though. You'll have to look into it. Skywest is also a WA airline which flies between the bigger towns - it's expensive but it may be the best option if you need to travel a long distance (from places like Broome to Perth would take several days by car so often a plane is a best choice!)
I suggest you find out where you'll be working ASAP to allow yourself to prepare for the weather and the culture. Wherever you go I'm sure it will be beautiful (WA is amazing) and a competely life-changing experience!!
Let me know if you have any more questions, and feel free to check out my blog for pictures of WA.